content: /* Copyright (C) 2016-2018 Alibaba Group Holding Limited
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  
  // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  package com.google.protobuf.util;
  
  import static com.google.common.math.IntMath.checkedAdd;
  import static com.google.common.math.IntMath.checkedSubtract;
  import static com.google.common.math.LongMath.checkedAdd;
  import static com.google.common.math.LongMath.checkedMultiply;
  import static com.google.common.math.LongMath.checkedSubtract;
  import static com.google.protobuf.util.Timestamps.MICROS_PER_SECOND;
  import static com.google.protobuf.util.Timestamps.MILLIS_PER_SECOND;
  import static com.google.protobuf.util.Timestamps.NANOS_PER_MICROSECOND;
  import static com.google.protobuf.util.Timestamps.NANOS_PER_MILLISECOND;
  import static com.google.protobuf.util.Timestamps.NANOS_PER_SECOND;
  
  import com.google.protobuf.Duration;
  import java.text.ParseException;
  import java.util.Comparator;
  
  /**
   * Utilities to help create/manipulate {@code protobuf/duration.proto}. All operations throw an
   * {@link IllegalArgumentException} if the input(s) are not {@linkplain #isValid(Duration) valid}.
   */
  public final class Durations {
    static final long DURATION_SECONDS_MIN = -315576000000L;
    static final long DURATION_SECONDS_MAX = 315576000000L;
  
    /** A constant holding the minimum valid {@link Duration}, approximately {@code -10,000} years. */
    public static final Duration MIN_VALUE =
        Duration.newBuilder().setSeconds(DURATION_SECONDS_MIN).setNanos(-999999999).build();
  
    /** A constant holding the maximum valid {@link Duration}, approximately {@code +10,000} years. */
    public static final Duration MAX_VALUE =
        Duration.newBuilder().setSeconds(DURATION_SECONDS_MAX).setNanos(999999999).build();
  
    private Durations() {}
  
    private static final Comparator<Duration> COMPARATOR =
        new Comparator<Duration>() {
          @Override
          public int compare(Duration d1, Duration d2) {
            checkValid(d1);
            checkValid(d2);
            int secDiff = Long.compare(d1.getSeconds(), d2.getSeconds());
            return (secDiff != 0) ? secDiff : Integer.compare(d1.getNanos(), d2.getNanos());
          }
        };
  
    /**
     * Returns a {@link Comparator} for {@link Duration}s which sorts in increasing chronological
     * order. Nulls and invalid {@link Duration}s are not allowed (see {@link #isValid}).
     */
    public static Comparator<Duration> comparator() {
      return COMPARATOR;
    }
  
    /**
     * Compares two durations. The value returned is identical to what would be returned by:
     * {@code Durations.comparator().compare(x, y)}.
     *
     * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if {@code x < y};
     *     and a value greater than {@code 0} if {@code x > y}
     */
    public static int compare(Duration x, Duration y) {
      return COMPARATOR.compare(x, y);
    }
  
    /**
     * Returns true if the given {@link Duration} is valid. The {@code seconds} value must be in the
     * range [-315,576,000,000, +315,576,000,000]. The {@code nanos} value must be in the range
     * [-999,999,999, +999,999,999].
     *
     * <p><b>Note:</b> Durations less than one second are represented with a 0 {@code seconds} field
     * and a positive or negative {@code nanos} field. For durations of one second or more, a non-zero
     * value for the {@code nanos} field must be of the same sign as the {@code seconds} field.
     */
    public static boolean isValid(Duration duration) {
      return isValid(duration.getSeconds(), duration.getNanos());
    }
  
    /**
     * Returns true if the given number of seconds and nanos is a valid {@link Duration}. The {@code
     * seconds} value must be in the range [-315,576,000,000, +315,576,000,000]. The {@code nanos}
     * value must be in the range [-999,999,999, +999,999,999].
     *
     * <p><b>Note:</b> Durations less than one second are represented with a 0 {@code seconds} field
     * and a positive or negative {@code nanos} field. For durations of one second or more, a non-zero
     * value for the {@code nanos} field must be of the same sign as the {@code seconds} field.
     */
    public static boolean isValid(long seconds, int nanos) {
      if (seconds < DURATION_SECONDS_MIN || seconds > DURATION_SECONDS_MAX) {
        return false;
      }
      if (nanos < -999999999L || nanos >= NANOS_PER_SECOND) {
        return false;
      }
      if (seconds < 0 || nanos < 0) {
        if (seconds > 0 || nanos > 0) {
          return false;
        }
      }
      return true;
    }
  
    /** Throws an {@link IllegalArgumentException} if the given {@link Duration} is not valid. */
    public static Duration checkValid(Duration duration) {
      long seconds = duration.getSeconds();
      int nanos = duration.getNanos();
      if (!isValid(seconds, nanos)) {
          throw new IllegalArgumentException(String.format(
              "Duration is not valid. See proto definition for valid values. "
              + "Seconds (%s) must be in range [-315,576,000,000, +315,576,000,000]. "
              + "Nanos (%s) must be in range [-999,999,999, +999,999,999]. "
              + "Nanos must have the same sign as seconds", seconds, nanos));
      }
      return duration;
    }
  
    /**
     * Convert Duration to string format. The string format will contains 3, 6, or 9 fractional digits
     * depending on the precision required to represent the exact Duration value. For example: "1s",
     * "1.010s", "1.000000100s", "-3.100s" The range that can be represented by Duration is from
     * -315,576,000,000 to +315,576,000,000 inclusive (in seconds).
     *
     * @return The string representation of the given duration.
     * @throws IllegalArgumentException if the given duration is not in the valid range.
     */
    public static String toString(Duration duration) {
      checkValid(duration);
  
      long seconds = duration.getSeconds();
      int nanos = duration.getNanos();
  
      StringBuilder result = new StringBuilder();
      if (seconds < 0 || nanos < 0) {
        result.append("-");
        seconds = -seconds;
        nanos = -nanos;
      }
      result.append(seconds);
      if (nanos != 0) {
        result.append(".");
        result.append(Timestamps.formatNanos(nanos));
      }
      result.append("s");
      return result.toString();
    }
  
    /**
     * Parse from a string to produce a duration.
     *
     * @return A Duration parsed from the string.
     * @throws ParseException if parsing fails.
     */
    public static Duration parse(String value) throws ParseException {
      // Must ended with "s".
      if (value.isEmpty() || value.charAt(value.length() - 1) != 's') {
        throw new ParseException("Invalid duration string: " + value, 0);
      }
      boolean negative = false;
      if (value.charAt(0) == '-') {
        negative = true;
        value = value.substring(1);
      }
      String secondValue = value.substring(0, value.length() - 1);
      String nanoValue = "";
      int pointPosition = secondValue.indexOf('.');
      if (pointPosition != -1) {
        nanoValue = secondValue.substring(pointPosition + 1);
        secondValue = secondValue.substring(0, pointPosition);
      }
      long seconds = Long.parseLong(secondValue);
      int nanos = nanoValue.isEmpty() ? 0 : Timestamps.parseNanos(nanoValue);
      if (seconds < 0) {
        throw new ParseException("Invalid duration string: " + value, 0);
      }
      if (negative) {
        seconds = -seconds;
        nanos = -nanos;
      }
      try {
        return normalizedDuration(seconds, nanos);
      } catch (IllegalArgumentException e) {
        throw new ParseException("Duration value is out of range.", 0);
      }
    }
  
    /** Create a Duration from the number of seconds. */
    public static Duration fromSeconds(long seconds) {
      return normalizedDuration(seconds, 0);
    }
  
    /**
     * Convert a Duration to the number of seconds. The result will be rounded towards 0 to the
     * nearest second. E.g., if the duration represents -1 nanosecond, it will be rounded to 0.
     */
    public static long toSeconds(Duration duration) {
      return checkValid(duration).getSeconds();
    }
  
    /** Create a Duration from the number of milliseconds. */
    public static Duration fromMillis(long milliseconds) {
      return normalizedDuration(
          milliseconds / MILLIS_PER_SECOND,
          (int) (milliseconds % MILLIS_PER_SECOND * NANOS_PER_MILLISECOND));
    }
  
    /**
     * Convert a Duration to the number of milliseconds. The result will be rounded towards 0 to the
     * nearest millisecond. E.g., if the duration represents -1 nanosecond, it will be rounded to 0.
     */
    public static long toMillis(Duration duration) {
      checkValid(duration);
      return checkedAdd(
          checkedMultiply(duration.getSeconds(), MILLIS_PER_SECOND),
          duration.getNanos() / NANOS_PER_MILLISECOND);
    }
  
    /** Create a Duration from the number of microseconds. */
    public static Duration fromMicros(long microseconds) {
      return normalizedDuration(
          microseconds / MICROS_PER_SECOND,
          (int) (microseconds % MICROS_PER_SECOND * NANOS_PER_MICROSECOND));
    }
  
    /**
     * Convert a Duration to the number of microseconds. The result will be rounded towards 0 to the
     * nearest microseconds. E.g., if the duration represents -1 nanosecond, it will be rounded to 0.
     */
    public static long toMicros(Duration duration) {
      checkValid(duration);
      return checkedAdd(
          checkedMultiply(duration.getSeconds(), MICROS_PER_SECOND),
          duration.getNanos() / NANOS_PER_MICROSECOND);
    }
  
    /** Create a Duration from the number of nanoseconds. */
    public static Duration fromNanos(long nanoseconds) {
      return normalizedDuration(
          nanoseconds / NANOS_PER_SECOND, (int) (nanoseconds % NANOS_PER_SECOND));
    }
  
    /** Convert a Duration to the number of nanoseconds. */
    public static long toNanos(Duration duration) {
      checkValid(duration);
      return checkedAdd(
          checkedMultiply(duration.getSeconds(), NANOS_PER_SECOND), duration.getNanos());
    }
  
    /** Add two durations. */
    public static Duration add(Duration d1, Duration d2) {
      checkValid(d1);
      checkValid(d2);
      return normalizedDuration(
          checkedAdd(d1.getSeconds(), d2.getSeconds()), checkedAdd(d1.getNanos(), d2.getNanos()));
    }
  
    /** Subtract a duration from another. */
    public static Duration subtract(Duration d1, Duration d2) {
      checkValid(d1);
      checkValid(d2);
      return normalizedDuration(
          checkedSubtract(d1.getSeconds(), d2.getSeconds()),
          checkedSubtract(d1.getNanos(), d2.getNanos()));
    }
  
    static Duration normalizedDuration(long seconds, int nanos) {
      if (nanos <= -NANOS_PER_SECOND || nanos >= NANOS_PER_SECOND) {
        seconds = checkedAdd(seconds, nanos / NANOS_PER_SECOND);
        nanos %= NANOS_PER_SECOND;
      }
      if (seconds > 0 && nanos < 0) {
        nanos += NANOS_PER_SECOND; // no overflow since nanos is negative (and we're adding)
        seconds--; // no overflow since seconds is positive (and we're decrementing)
      }
      if (seconds < 0 && nanos > 0) {
        nanos -= NANOS_PER_SECOND; // no overflow since nanos is positive (and we're subtracting)
        seconds++; // no overflow since seconds is negative (and we're incrementing)
      }
      Duration duration = Duration.newBuilder().setSeconds(seconds).setNanos(nanos).build();
      return checkValid(duration);
    }
  }
  